Fan wheel



ay 8, .1945. F. M; GRAHAM FAN WHEEL Filed Feb. 19, 1942 Patented May 8, 1945 UNITED STATEE ATENT OFFICE g FAN WHEEL Franklvi. Graham, Indianapolis, Ind. Application February 19-, 1942, Serial No. 431,506

' i 7 Claims. (01. 179-168) This invention relates to what is commonly known as a propeller'or disc type fan. wheel which has its air intake and air discharge apperiphery of the fan Wheel.

One chief feature of the invention consists in providing a peripheral frame element from which the bucket-like blades of the fan are primarily supported and these blades are of such area that the resulting fan is comparativelyopen in the center and as illustrated herein, this open center is substantially the middle'half of the fan, all as will be more fully pointed out hereinafter.

Another feature of the invention is the lapping of the bucket-like blades at the rim 8r peripheral frame portion of the fan wheel.

Other objects and features of the invention will be set forth more fully hereinafter.

The full nature'of the invention will be understood from the accompanying drawing and the followingdescriptionand claims:

In the drawing, a

Fig. 1 is a front view looking at a fan wheel embodying the invention.

Fig. 2 is a substantially central sectional view taken on line 2-2 of Fig. 1 and in the direction of the arrows.

Fig. 3 is a view similar toFi 2 and of a modified form of the invention. j

In Figs. 1 and 2 of the drawing, I'll indicates a circular band or rim, herein shown-substantially of rectangular cross-section stock. Extending inwardly therefrom and radially, are thespoke or spider forming arms H which attheir outer ends extend through apertures .inithe band: or rim, and are rivetedas at 12. The inner ends of these spider arms are herein shown threaded as indicated at l3.

A hub I4 is provided with radially extending Herein four spider arms are illustrated. The minimum number is always preferred due to the fact that the arms in the rotation of the wheel create noise turbulence, et cetera'.

Extending inwardly from the band or frame are short arms l9 and these short arms are similarly secured by riveting 2B, or the like, to the band or frame It. Herein four spider arms are illustrated and four shortarms are illustrated,

all the arms being equally and arcuately spaced and all being radially arranged and with the short arms being positioned between the spider arms.

As shown in Fig. 1, each fan blade 22 has a radial portion 23 which is substantially tubularlike in character and encircles the adjacent ra'- dial arm portion. The peripheral edge, indicated by the numeral 24, of each bladeis suittapped holes I5 to receive the threaded ends l3 of the arms II. The hub I4 is of the desired diameter and has the desired overall length. It includes a central bore l6 and is provided with a tapped hole, or the like, ll that receives a set screw l8 for rigidly connecting the hub to a power shaft, not shown, and. receivable by the bore I 6 of said hub.

ably secured to the inside face of the rim. This may be by spot welding, not shown, riveting, or the like. It, of course, is to beunderstood that the flange of the fan blade is cut away to clear the blade lapped radial arm since the fan blade extends arcuately fromone radial arm to an appreciable distance beyond the next or adjacent radial arm, as indicated by the numeral'ii. It thus will be apparent that theblade body and flange portions of two adjacent blades lap each other to an amount substantially equal to the overlap between the blades. The blades are spaced apart axially, as it were, whereas the lapping flanges abut. V

The edge 26 of each blade from the tubelike end 23 to the rim or band ill may be of any desired character but herein it is shown. as generally of the type known as a slight reverse curve. In other words, the portionclosest to the end 23 is curved outwardly or convex with relation to the blade and the portion closest to the rim is curved inwardly or concavely with reference to the blade, the two curvatures merging. with. each other approximately where the .bla'de'ie'dge 2t would-be intersected by a plane includinglthe axis of the hub and the radial armzlappe'dxby the blade, which is the arm adjacent the radial arm supporting that particular blade.

.As indicated in Fig. 1, the radial distance of the closest portion of the blade to the hub may be generally designated by R/Z, whereas the rim is illustrated as at a distance R from the axis of the hub. Therefore, there is provided a substantially free central openin except for the hub and the spider arms I i, and this central opening has a diameter substantially equal to the radius of the rim or band. Therefore, the central opening may be said to be about half that of the fan Wheel, although as to area the aforesaid statement does not apply.

Reference now will be had to Fig. 3. In this form of the invention the band is indicated by the numeral lit, the hub by H4, the set screw type of anchorage by I I1 and i l8. Extending inwardly from the rim and suitably secured thereto as at I29 are the radially directed and equally arcuately spaced arms H9. None of the same in this form of the invention extend inwardly to the hub but terminate at the end of the tubular portion I23 of the fan [blade I22.

The hub and fan are connected by a suitable number of arcuately spaced and outwardly directed supporting arms I l l, which herein are not associated with any tubular portion of any blade but said arms lie rearwardly of the same and are curved forwardly and outwardly as at Illa and thence, are directed forwardly as at H'ib. The outer ends of said arms are Welded as at 1 I2 to the rim H6. The inner or hub secured ends of the arms ill may be threaded into the hub as shown in Figs. 1 and 2 or may be welded thereto as indicated at H3. i

This form of the invention differs from that shown in Figs. 1 and 2 in that the hub portion in the first form of the invention is included between the front and rear planes of th fan wheel structure, whereas in the form of the invention shown in Fig. 3, the hub structure is positioned substantially at one of the aforesaid limiting planes.

Each of these structures may be used to advantage over the other structure for certain types of installations wherein certain clearances are required both as to power shaft mounting and as to wheel clearance required with reference to the power supply. The power for the shaft, not shown, may be an electricmotor, a shaft with pulley and [belt driven, or any other equivalent form of power; It is also to be observed that while a set screw is shown as the means for securing the hub to the power shaft, any other desired or equivalent construction may be utilized in lieu thereof.

While the radial arms of both characters shown in Figs. 1 and 2 are shown as round rod, they may be of any cross sectional type, if desired, and when of such other shape, the tubular portion 23 naturally would be of complementary character. i

In the form of the invention shown in Fig. 3, the aforesaid statement also applies with reference to th arms H9.- With respect to the rim supporting arms Hi, the cross-sectional shape of these may be strap or rectangular, oval or fiat curved type, all without departing from the invention.

While the invention has been illustrated and described in great detail in the drawing and foregoing description, the same is'to be considered as illustrative and not restrictive in character.

The several modifications described herein as well as others which will readily suggest themselves to persons skilled in this art, all are considered to be within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

l. A fan wheel including a peripheral rim of considerable diameter, a plurality of arcuately spaced arms rigid with said rim and extending substantially radially inward therefrom and terminating at a considerable distance remote from the wheel axis and at a point from said rim approximately no greater than half the radius, a hub of comparatively small diameter and adapted for power shaft connection, a plurality of appreciably longer arms extending radially outwardly from the hub and secured at their outer ends to said rim, the first mentioned arms inner ends being free of said hub, and scupper-like fan blades each having an edge contiguous to the rim and secured thereto and of a peripheral length at least and a radial rear edge portion secured to an arm and approximately of the length of the shorter arms, each blade'being somewhat triangular-like in general outline, the blades each extending inwardly from the rim to a point between the hub axis and the rim and having the hub closest portion of the blade immediately adjacent a circle including the inner free ends of the first mentioned arms to form a comparatively unobstructed central channel about said hub and within said blades.

2. A fan wheel as defined by claim 1 wherein each blade has its outermost peripheral tip portion lapping the preceding blade rearward radial edge portion.

3. A fan wheel as defined by claim 1 wherein the free inner and forward edge of each blade is of reverse curve type.

4. A fan wheel as defined by claim 1 wherein each. blade has its outermost peripheral tip portion lapping the preceding blade rearward radial edge portion and the free inner and forward edge of blade is of reverse curve type, the junction oi the reverse curves being juxtapositioned to the radial rear edge ofthe lapped blade.

5. A fan wheel as defined by claim 1 wherein the longer arms are each curved at their outer ends for positioning the hub to one side of the wheel, the radial edge of each blade being connected to a short arm.

6. A fan wheel as defined'by claim 1 wherein the radial rear edges of certain blades'are each connected to a shorter arm and wherein the radial rear edges of other of the blades are each. connectedto alonger arm. g p

7. A fan wheel as defined by claim 1 wherein the radial rear edges of certain blades are each connected to a shorter arm and wherein the radial rear edges of other of the blades are each connected to a longer arm andthe longer and shorter arms are alternated. 1.

. 1 FRANK M. GRAHAM. 

